diff options
| author | Stephen Warren <swarren@nvidia.com> | 2012-07-25 17:34:37 -0600 |
|---|---|---|
| committer | Rob Herring <rob.herring@calxeda.com> | 2012-08-03 08:01:46 -0500 |
| commit | 5d61b165c892853f2daf6220d2ec6577487e273a (patch) | |
| tree | 3bcff9b185383c768b702461c1194cb8eb9d0002 /drivers/of/address.c | |
| parent | 0d7614f09c1ebdbaa1599a5aba7593f147bf96ee (diff) | |
of: Allow busses with #size-cells=0
It's quite legitimate for a DT node to specify #size-cells=0. One example
is a node that's used to collect a number of non-memory-mapped devices.
In that scenario, there may be multiple child nodes with the same name
(type) thus necessitating the use of unit addresses in node names, and
reg properties:
/ {
regulators {
compatible = "simple-bus";
#address-cells = <1>;
#size-cells = <0>;
regulator@0 {
compatible = "regulator-fixed";
reg = <0>;
...
};
regulator@1 {
compatible = "regulator-fixed";
reg = <1>;
...
};
...
};
};
However, #size-cells=0 prevents translation of reg property values into
the parent node's address space. In turn, this triggers the kernel to
emit error messages during boot, such as:
prom_parse: Bad cell count for /regulators/regulator@0
To prevent printing these error messages for legitimate DT content, a
number of changes are made:
1) of_get_address()/of_get_pci_address() are modified only to validate
the value of #address-cells, and not #size-cells.
2) of_can_translate_address() is added to indicate whether address
translation is possible.
3) of_device_make_bus_id() is modified to name devices based on the
translated address only where possible, and otherwise fall back to
using the (first cell of the) raw untranslated address.
4) of_device_alloc() is modified to create memory resources for a device
only if the address can be translated into the CPU's address space.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Diffstat (limited to 'drivers/of/address.c')
| -rw-r--r-- | drivers/of/address.c | 27 |
1 files changed, 23 insertions, 4 deletions
diff --git a/drivers/of/address.c b/drivers/of/address.c index 7e262a6124c5..7a07751428de 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -9,8 +9,8 @@ /* Max address size we deal with */ #define OF_MAX_ADDR_CELLS 4 -#define OF_CHECK_COUNTS(na, ns) ((na) > 0 && (na) <= OF_MAX_ADDR_CELLS && \ - (ns) > 0) +#define OF_CHECK_ADDR_COUNT(na) ((na) > 0 && (na) <= OF_MAX_ADDR_CELLS) +#define OF_CHECK_COUNTS(na, ns) (OF_CHECK_ADDR_COUNT(na) && (ns) > 0) static struct of_bus *of_match_bus(struct device_node *np); static int __of_address_to_resource(struct device_node *dev, @@ -182,7 +182,7 @@ const __be32 *of_get_pci_address(struct device_node *dev, int bar_no, u64 *size, } bus->count_cells(dev, &na, &ns); of_node_put(parent); - if (!OF_CHECK_COUNTS(na, ns)) + if (!OF_CHECK_ADDR_COUNT(na)) return NULL; /* Get "reg" or "assigned-addresses" property */ @@ -490,6 +490,25 @@ u64 of_translate_dma_address(struct device_node *dev, const __be32 *in_addr) } EXPORT_SYMBOL(of_translate_dma_address); +bool of_can_translate_address(struct device_node *dev) +{ + struct device_node *parent; + struct of_bus *bus; + int na, ns; + + parent = of_get_parent(dev); + if (parent == NULL) + return false; + + bus = of_match_bus(parent); + bus->count_cells(dev, &na, &ns); + + of_node_put(parent); + + return OF_CHECK_COUNTS(na, ns); +} +EXPORT_SYMBOL(of_can_translate_address); + const __be32 *of_get_address(struct device_node *dev, int index, u64 *size, unsigned int *flags) { @@ -506,7 +525,7 @@ const __be32 *of_get_address(struct device_node *dev, int index, u64 *size, bus = of_match_bus(parent); bus->count_cells(dev, &na, &ns); of_node_put(parent); - if (!OF_CHECK_COUNTS(na, ns)) + if (!OF_CHECK_ADDR_COUNT(na)) return NULL; /* Get "reg" or "assigned-addresses" property */ |